Piano key tensioning device



Sept. 12, 1961 A. E. RICE 2,999,411

PIANO KEY TENSIONING DEVICE Filed May 20, 1960 FIG. 1

3 M (P-LAW /Z V A/ /g/ )f /5 0 20 FIG. 2.

FIG. 4.

INVENTOR. 42

ATTOE/VEYS.

United States Patent 2,999,411 PIANO KEY TENSIONING DEVICE Arlo E. Rice, P.O. Box 1027, Baird, Tex. Filed May 20, 1960, Ser. No. 30,570 6 Claims. (Cl. 84439) This invention relates to a novel piano key tensioning device.

The primary object of the invention is the provision of a tensioning device of the kind indicated whereby a key can be tensioned toward its elevated position, so as to increase the amount of finger pressure required to depress the key in playing a piano, so as to enable a player to obtain the desired key action; and so as to eliminate sticking and sluggish key action.

Another object of the invention is to provide efiicient, simple, and easily installed devices of the character indicated, which involve spring means which are easily, quickly, and widely adjustable to produce a wide range of key actions. 7

Other important objects and advantageous features of the invention will be apparent from the following description and the accompanying drawings, wherein, for purposes of illustration only, a specific form of the invention is set forth in detail.

In the drawings:

FIGURE 1 is a fragmentary vertical section taken through a piano mechanism, showing a key in side elevation, with a tensioning device of the invention installed relative thereto;

FIGURE 2 is a fragmentary top plan view of FIGURE 1, partly in section;

FIGURE 3 is an enlarged fragmentary vertical section taken on the line 3-3 of FIGURE 2; and,

FIGURE 4 is a side elevation of the spring member, per se.

Referring in detail to the drawings, wherein like numerals designate like parts throughout the several views, there are shown therein a piano mechanism base or board upon which are secured a forward rail 12, a balance rail 14, and a back rail 16, these rails having felts 18, fail, 22 thereon. Upstanding from the balance rail 14 is a hollow vertical pin 24 having a vertical bore 26 opening to its upper end 28, which replaces the usual solid piano key supporting pin (not shown), over which an upwardly flared bore 30, in an intermediate part of a piano key 32 is supportably engaged. The key 32 normally rests, at its rear end, on the back rail felt 22, and is spaced upwardly, at its forward end, as shown in FIGURE 1, from the forward rail felt 18, with the intermediate part of the key bearing upon the balance rail felt 20.

The hollow pin 24 serves as the mounting for a ten sioning spring 34 which comprises a coil 36, preferably of at least one full convolution of suitable spring wire, preferably of metal, from opposite ends of which extend, preferably tangentially to the coil 36, a relatively short vertical arm 38 and a relatively long generally horizontal arm 40.

As shown in FIGURE 4, the short arm 38 is slightly longitudinally bowed between the ends, in a direction away from the long arm 40, and terminates at its free end in a return bend 42 toward the laterally outward side of the short arm 38. The bend 42 provides a rounded terminal of substantial cross-section to facilitate downward insertion of the short arm 38 in the bore 26 of the pin 24 and when therein to have substantial sliding and frictional engagement with the sidewall of the pin bore, as shown in FIGURE 3. The bowing of the short arm 38 is greater in radius than the diameter of the pin bore 26, so that, as also shown in FIGURE 3, insertion of are arm 38 downwardly in the pin bore 26 produces compression of the arm 38, so that the terminal 42 and an intermediate portion 44 bear forcibly and frictionally against opposite sides of the pin bore 26, for frictionally anchoring the arm 38 in different vertically adjusted positions in the pin 24.

The long arm 40 of the spring 34 is preferably initially straight throughout the major portion of its length, as shown in FIGURE 4, and has on its free end a longitudinally and upwardly curved terminal 46. Before installation of the spring '34, the arms 38 and 40 are in relatively closely divergent tensioned relationship, as also shown in FIGURE 4.

The spring 34 is installed simply by forcing the short arm 38 downwardly in the bore 26 of the pin 24, with the terminal 46 of the lug arm 40 bearing upon the upper surface of the piano key 32, at a location preferably substantially midway between the balance rail and the back rail. Forcing the short arm 38 deeply into the pin 24 increases the spring pressure of the long arm 40 upon the piano key, and moving the short arm 38 upwardly in the pin 24 decreases the spring pressure of the long arm 40 on the piano key 32, so as to correspondingly increase and decrease the amount of finger pressure on the forward end of the key, required to depress or play the key. It is obvious that tensioning devices of the present invention are adapted to be installed on all of the keys, including the sharps, fiats, and naturals, or only on selected keys.

While there has been shown and described herein a preferred form of the invention, it is to be understood that the invention is not necessarily confined thereto, and that any change or changes in the structure of and in the relative arrangements of components thereof are contemplated as being within the scope of the invention as defined by the claims appended hereto.

What is claimed is:

1. In combination, a piano mechanism base, a forward rail, a balance rail, and a back rail spacedly supported on said base, a piano key overlying and extending across said rails, said key having a forward end portion overlying said forward rail, an intermediate portion overlying said balance rail, and a rear end portion overlying said back rail, said key having a vertical bore extending through its intermediate portion, a vertical pin secured to the balance rail and rising through said bore, and a tensioning spring mounted on said pin and downwardly tensioned upon the key behind the pin, said spring comprising a coil, a vertical arm carried by said pin and a downwardly tensioned horizontal arm extending rearwardly from the vertical arm and having a terminal tensioned downwardly upon the upper surface of the key.

2. In combination, a piano mechanism having a forward rail, a balance rail, and a back rail, a piano key extending across and overlying said rails, means rockably mounting the key on the balance rail, the key being normally rearwardly overbalanced with its rear end resting upon the back rail and its forward end spaced upwardly from the forward rail, said mounting means comprising a vertical bore extending through the key, a vertical pin fixed to the balance rail and rising through said bore, said pin having an axial bore opening to its upper end, and a spring having a first arm securably engaged in said axial bore and a second arm extending rearwardly from the pin and downwardly tensioned on the key.

3. In combination, a piano mechanism having a forward rail, :1 balance rail, and a back rail, a piano key extending across and overlying said rails, means rockably mounting the key on the balance rail, the key being normally rearwardly overbalanced with its rear end resting upon the back rail and its forward end spaced upwardly from the forward rail, said mounting means comprising a vertical bore extending through the key, a vertical pin fixed to the balance rail and rising through said bore, said pin having an axial bore opening, to its upper end, and a spring having a first arm securably engaged in said axial bore and a second arm extending rearwardly from the pin and downwardly tensioned on the key, said first ann being vertically adjustable in the bore of the pin for adjusting the tension of the second arm on the key.

4. In combination, a piano mechanism having a for- Ward rail, a balance rail, and a back rail, a piano key extending across and overlying said rails, means rockably mounting the key on the balance rail, the key being normally rearwardly overbalanced with its'rear end resting upon the back rail and its forward end spaced upwardly from the forward rail,. said mounting means comprising a vertical boreextending through the key, a vertical' pin fixed to the balance rail and rising through said bore, said pin'having an axial bore opening to its upper end, and a spring having a first arm securably engaged in said axial bore and a second arm extending rearwardly from the pin and downwardly tensioned on the key, said first arm being vertically adjustable in the bore of the pin for adjusting the tensionof the second arm on the key, and means securing said first arm frictionally and slidably in the pin bore.

5. In combination, a piano mechanism having a forward rail, a balance rail, and a back rail, a piano key extending across and overlying said rails, means rockably mounting the key on thebalance. rail, the key being normally rearwardly overbalanced with its rear end resting upon the back rail and its forward end spaced upwardly from'the forward rail, said mounting means comprising a vertical bore extending through the key, a vertical pin fixed to the balance rail and rising through ,4 said'bore, said pin having an axial bore opening to its upper end, and a spring having a first arm securably engaged in said axial bore and a second arm extending rearwardly from the pin and downwardly tensioned on the key, said first arm being vertically adjustable in the bore of the pin for adjusting the tension of the second arm on the key, said first arm having a pin bore entering terminal on its free end and having a longitudinally bowed portion between its ends, the radius of the bowed portion being greater than the diameter of the pin bore.

6. In combination, a piano mechanism having a forward rail, a balance rail, and a back rail, a piano key extending across and overlying said rails, means rockably mounting the key on the balance rail, the key being normally rearwardly overbalanced with its rear end resting upon the back rail and its forward end spaced upwardly from the forward rail, said mounting means comprising a vertical bore extending through the key, a vertical pin fixed to the balance rail and rising through said bore, said pin having an axial bore opening to its upper end, and a spring having a first arm securably engaged in said axial bore and a second'arm extending rearwardly from the pin and downwardly tensioned on the key, said first arm being vertically adjustable in the bore of the pin for adjusting the tension of the second arm on the key, said first arm having a pin bore entering terminal on its free end and having a longitudinally bowed portion between its ends, the radius of the bowed portion being greater than the diameter of the pin bore, said spring having a coil having ends to which said first and second arms are severally connected.

Felldin Sept. 21, 1880 Hadden Aug. 19, 1952 

